1. Field of the Invention
The invention relates to a physical unclonable function (PUF) circuit, and more particularly to a PUF circuit based on a zero temperature coefficient (ZTC) point of a metal oxide semiconductor field effect transistor (MOSFET).
2. Description of the Related Art
The PUF is designed based on weak deviation of the process parameters in manufacture of the integrated circuit. The function performance of the circuit tends to be affected by the supply voltage, temperature, and aging factors. Robustness is a nature that the PUF circuit works normally under different factors and that seriously influences the security of the application system. A typical method for improving the robustness of the PUF circuit includes adopting an error-correcting circuit and changing the operation sequence of the circuit, which, however, consumes a large circuit area.